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<h2 class="chapter" id="RTL-Representation"><span>14 RTL Representation<a class="copiable-link" href="#RTL-Representation"> &para;</a></span></h2>
<a class="index-entry-id" id="index-RTL-representation"></a>
<a class="index-entry-id" id="index-representation-of-RTL"></a>
<a class="index-entry-id" id="index-Register-Transfer-Language-_0028RTL_0029"></a>

<p>The last part of the compiler work is done on a low-level intermediate
representation called Register Transfer Language.  In this language, the
instructions to be output are described, pretty much one by one, in an
algebraic form that describes what the instruction does.
</p>
<p>RTL is inspired by Lisp lists.  It has both an internal form, made up of
structures that point at other structures, and a textual form that is used
in the machine description and in printed debugging dumps.  The textual
form uses nested parentheses to indicate the pointers in the internal form.
</p>

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<li><a href="RTL-Objects.html" accesskey="1">RTL Object Types</a></li>
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<li><a href="Accessors.html" accesskey="3">Access to Operands</a></li>
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